From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F3A0D1E511; Thu, 8 Jan 2026 01:29:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767835760; cv=none; b=EpYT8wXBjaY6Ct5hQjL99K9R1rScG9Ni7W3ALCZK/8fUEtNbZXHk1FZaAS2r0G8MSy0Y2pyHxLIcnFRrvw2Ywo5X1JL9yewApUjXlqIFrfGBl3NDRuRbx3ia6zeUvj4+WP49/fjEO2uUA/svj06B+X+XoMq9t4wpFk6585uw2Po= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767835760; c=relaxed/simple; bh=F6Ydwq3mfkWXzvZIrp1ucG0FulrTWaNCAfgFyTNkPbs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=I0LyhJeTw6944AdQ1pn26XpD6sQcGoVQkn+4NHUfC6gqQxqdo8GmilitBxaFD7YvdbyjBhNG404Em5qouEYU+voo+3adSEXwsQHqNz1hrMkSuARJogpxjVxdOJG9334flHlXlclKPXhhq2brG6II/ijWV0buSUSS/ijVCSfArUg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=YDWvhEUu; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="YDWvhEUu" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1767835753; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=UXDaSi1/LDpEkmhDCd4oaUbfPpfa1uXY5JlPhY3BLZQ=; b=YDWvhEUujIzKtObiZqlVs76fM6rwPq0k6Fmg9GP4S03qJwadn4fNUGbr84xDwMCI9PkxtfLWUJj4TueGY/Syc44xWsDSrwPHtixwyGisiHcLdYGs3X6KKHljvaW47OqKXyEwnCuIEDLT+2Qzz0C73cMURyzD8u3F2l495D938g4= Received: from 30.221.145.71(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0WwamNmk_1767835752 cluster:ay36) by smtp.aliyun-inc.com; Thu, 08 Jan 2026 09:29:12 +0800 Message-ID: <94b4189d-dfb6-4443-a336-abbae89d36ad@linux.alibaba.com> Date: Thu, 8 Jan 2026 09:29:11 +0800 Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ocfs2: Fix circular locking dependency in ocfs2_del_inode_from_orphan() To: Prithvi Tambewagh , mark@fasheh.com, jlbec@evilplan.org, Heming Zhao Cc: heming.zhao@suse.com, ocfs2-devel@lists.linux.dev, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linux.dev, skhan@linuxfoundation.org, david.hunter.linux@gmail.com, khalid@kernel.org, syzbot+78359d5fbb04318c35e9@syzkaller.appspotmail.com References: <20260106125100.327980-1-activprithvi@gmail.com> From: Joseph Qi In-Reply-To: <20260106125100.327980-1-activprithvi@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2026/1/6 20:51, Prithvi Tambewagh wrote: > A possible circular locking dependency in ocfs2_del_inode_from_orphan() > is detected by syzbot, which occurs due to change in the sequence of > acquiring locks. The existing chain is: > > &ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] --> &dquot->dq_lock --> > &ocfs2_quota_ip_alloc_sem_key > > In ocfs2_dio_end_io_write(), &ocfs2_quota_ip_alloc_sem_key is acquired, > and then ocfs2_del_inode_from_orphan() is called, which acquires > &ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]. This opposes the > existing dependency chain: > IIUC, ocfs2_dio_end_io_write() only gets the &ocfs2_file_ip_alloc_sem_key. So how it happens? Thanks, Joseph > -> #3 (&ocfs2_quota_ip_alloc_sem_key){++++}-{4:4}: > lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 > down_write+0x3a/0x50 kernel/locking/rwsem.c:1590 > ocfs2_create_local_dquot+0x19d/0x1a40 fs/ocfs2/quota_local.c:1227 > ocfs2_acquire_dquot+0x80f/0xb30 fs/ocfs2/quota_global.c:883 > dqget+0x7c1/0xf20 fs/quota/dquot.c:980 > __dquot_initialize+0x3b3/0xcb0 fs/quota/dquot.c:1508 > ocfs2_get_init_inode+0x13b/0x1b0 fs/ocfs2/namei.c:205 > ocfs2_mknod+0x863/0x2050 fs/ocfs2/namei.c:313 > ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:676 > lookup_open fs/namei.c:3796 [inline] > open_last_lookups fs/namei.c:3895 [inline] > path_openat+0x1500/0x3840 fs/namei.c:4131 > do_filp_open+0x1fa/0x410 fs/namei.c:4161 > do_sys_openat2+0x121/0x1c0 fs/open.c:1437 > do_sys_open fs/open.c:1452 [inline] > __do_sys_openat fs/open.c:1468 [inline] > __se_sys_openat fs/open.c:1463 [inline] > __x64_sys_openat+0x138/0x170 fs/open.c:1463 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > -> #2 (&dquot->dq_lock){+.+.}-{4:4}: > lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 > __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] > mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 > wait_on_dquot fs/quota/dquot.c:357 [inline] > dqget+0x73a/0xf20 fs/quota/dquot.c:975 > __dquot_initialize+0x3b3/0xcb0 fs/quota/dquot.c:1508 > ocfs2_get_init_inode+0x13b/0x1b0 fs/ocfs2/namei.c:205 > ocfs2_mknod+0x863/0x2050 fs/ocfs2/namei.c:313 > ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:676 > lookup_open fs/namei.c:3796 [inline] > open_last_lookups fs/namei.c:3895 [inline] > path_openat+0x1500/0x3840 fs/namei.c:4131 > do_filp_open+0x1fa/0x410 fs/namei.c:4161 > do_sys_openat2+0x121/0x1c0 fs/open.c:1437 > do_sys_open fs/open.c:1452 [inline] > __do_sys_openat fs/open.c:1468 [inline] > __se_sys_openat fs/open.c:1463 [inline] > __x64_sys_openat+0x138/0x170 fs/open.c:1463 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > -> #1 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}: > lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 > down_write+0x3a/0x50 kernel/locking/rwsem.c:1590 > inode_lock include/linux/fs.h:980 [inline] > ocfs2_remove_inode fs/ocfs2/inode.c:731 [inline] > ocfs2_wipe_inode fs/ocfs2/inode.c:894 [inline] > ocfs2_delete_inode fs/ocfs2/inode.c:1155 [inline] > ocfs2_evict_inode+0x153d/0x40d0 fs/ocfs2/inode.c:1295 > evict+0x504/0x9c0 fs/inode.c:810 > do_unlinkat+0x39f/0x570 fs/namei.c:4744 > __do_sys_unlinkat fs/namei.c:4778 [inline] > __se_sys_unlinkat fs/namei.c:4771 [inline] > __x64_sys_unlinkat+0xd3/0xf0 fs/namei.c:4771 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > -> #0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}: > check_prev_add kernel/locking/lockdep.c:3165 [inline] > check_prevs_add kernel/locking/lockdep.c:3284 [inline] > validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 > __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 > lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 > down_write+0x3a/0x50 kernel/locking/rwsem.c:1590 > inode_lock include/linux/fs.h:980 [inline] > ocfs2_del_inode_from_orphan+0x134/0x740 fs/ocfs2/namei.c:2730 > ocfs2_dio_end_io_write fs/ocfs2/aops.c:2306 [inline] > ocfs2_dio_end_io+0x47b/0x1100 fs/ocfs2/aops.c:2404 > dio_complete+0x25e/0x790 fs/direct-io.c:281 > __blockdev_direct_IO+0x2bc0/0x31f0 fs/direct-io.c:1303 > ocfs2_direct_IO+0x260/0x2d0 fs/ocfs2/aops.c:2441 > generic_file_direct_write+0x1dc/0x3e0 mm/filemap.c:4189 > __generic_file_write_iter+0x120/0x240 mm/filemap.c:4358 > ocfs2_file_write_iter+0x157d/0x1d20 fs/ocfs2/file.c:2469 > iter_file_splice_write+0x97a/0x10f0 fs/splice.c:738 > do_splice_from fs/splice.c:938 [inline] > direct_splice_actor+0x104/0x160 fs/splice.c:1161 > splice_direct_to_actor+0x5b3/0xcd0 fs/splice.c:1105 > do_splice_direct_actor fs/splice.c:1204 [inline] > do_splice_direct+0x187/0x270 fs/splice.c:1230 > do_sendfile+0x4ec/0x7f0 fs/read_write.c:1370 > __do_sys_sendfile64 fs/read_write.c:1431 [inline] > __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > Fix this by acquiring &ocfs2_quota_ip_alloc_sem_key after acquiring > &ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE], effectively calling > down_write(&oi->ip_alloc_sem) after the call to > ocfs2_del_inode_from_orphan(). > > Reported-by: syzbot+78359d5fbb04318c35e9@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=78359d5fbb04318c35e9 > Tested-by: syzbot+78359d5fbb04318c35e9@syzkaller.appspotmail.com > Cc: stable@vger.kernel.org > Signed-off-by: Prithvi Tambewagh > --- > fs/ocfs2/aops.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c > index 76c86f1c2b1c..586e3b74d782 100644 > --- a/fs/ocfs2/aops.c > +++ b/fs/ocfs2/aops.c > @@ -2295,8 +2295,6 @@ static int ocfs2_dio_end_io_write(struct inode *inode, > goto out; > } > > - down_write(&oi->ip_alloc_sem); > - > /* Delete orphan before acquire i_rwsem. */ > if (dwc->dw_orphaned) { > BUG_ON(dwc->dw_writer_pid != task_pid_nr(current)); > @@ -2309,6 +2307,8 @@ static int ocfs2_dio_end_io_write(struct inode *inode, > mlog_errno(ret); > } > > + down_write(&oi->ip_alloc_sem); > + > di = (struct ocfs2_dinode *)di_bh->b_data; > > ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh); > > base-commit: 765e56e41a5af2d456ddda6cbd617b9d3295ab4e